Fastening device and method for making the same



Dec 24, 1940.

A BOGGILD 'ETAL 2,225,607 FASTENING DEVICE AND METHOD FOR MAKING THE SAME Filed Oct 11, 1938 In vento rs: Axel 'Boggild, 7 John D uch,

Th e h Atbo'r'ne Patented Dec. 24, 1940 PATENT OFFICE FASTENING DEVICE AND METHOD FOR MAKING THE SAME Axel Boggild, Trumbull, and John Duch, Bridgeport, Conn., assignors to General Electric Company, a corporation of New York Application October 11, 1938, Serial No. 234,426

5 Claims.

The present invention relates to fastening devices produced by the rolling process, and to the method of manufacturing the fastening devices.

In the rolling process a blank is rolled between cooperating dies which form fastening projections on the body of the blank. These projections may be in the form of threads, ribs or knurls. For convenience in manufacture, the cooperating dies are arranged with their faces inclined from the horizontal and the blank is provided with a head which projects over the upper edges of the dies. The head locates the body of the blank with respect to the die and facilitates the feeding of the blank to the dies. In the manufacture of fasteners having no head the feeding of the blanks to the dies is much more difficult. For this reason headless fasteners are more expensive to manufacture.

The objectof our invention is to provide an improved construction in headless fasteners and an improved method for making the same. For a consideration of what I believe to be novel and our invention, attention is directed to the following description and the claims appended thereto.

In the drawing, Fig. 1 is a plan view of a machine embodying our invention for the manufacture of fastening devices; Fig. 2 is a perspective view of the dies used in the machine of Fig. 1; Fig. 3 is a perspective view of the blank from which the fastener is made; and Fig. 4 is a perspective view of the completed fastener.

Referring to Fig. 1, the machine has a reciprocating slide l carrying a die 2 which is held in the slide by means of a clamp 3. The clamp may be loosened o-r tightened by a stud 4. An adjustable holder 5 carries a stationary die 6 which is held in position by a clamp 1 which may be loosened or tightened by means of a stud 8. On the upper edges of the dies 2 and 6 are secured plates 9, the upper edges of which are cut at one end to provide inclined surfaces I which merge gradually into the plain edge portions ll of the plates. The surfaces l0 are for the purpose of receiving the head of the blank at the start of the rolling operation, as shown in Figs. 1 and 2. The blank, shown in Fig. 3, comprises a cylindrical body portion [2 and a relatively thin, fin-like head l3 at one end projecting radially outward from the periphery of the body portion. The dies are arranged so that their thread forming faces are inclined to the horizontal and so that the plates 9 at the edges are uppermost. With this arrangement, the blank can be fed by gravity to the dies and the thin head l3 of the blank will rest against the surfaces In and will locate the body of the blank with reference to the thread forming faces of the dies.

In the manufacture of the fastener, a blank is placed adjacent the right-hand end of the stationary die 6 with its head l3 resting on the surfaces it]. As the die 2 moves to the left with the reciprocating slide I, a starter rod I4 moves the blank to the left on the face of the die 6. The body ll of the blank is then gripped by the moving die 2 and rotates across the face of the die 6 during which movement a thread is rolled on the body of the blank by the projections on the die faces. The form of the fastener projections rolled on the body of the blank is not material to the present invention. In the movement of the die 2 the blank is rotated so that the die moves faster than the blank. The right-hand end of the moving die 2 is shown in dotted lines in Fig. 1 just as the blank, also shown in dotted lines, passes from the left-hand end of the die 6. The fastener then passes to a receiving receptacle which is not shown on the drawing. During the rolling operation the head I3 of the blank is rolled against the surfaces l0 and H on the plates 9 at the upper edges of the die, as indicated in Fig. 2. The inclined surfaces l0 act on the under side of the edges of the head and roll or bend the edges of the head displacing them radially inward and axially outward from theperiphery of the fastener body to form a hollow cylindrical portion l extending axially beyond one end of the fastener body. The surfaces I!) turn the edges of the head outward so that they can be rolled to a cylindrical shape by the surfaces II. By this arrangement an improved headless fastener is obtained which may be easily and cheaply made by the thread .rolling machines in general use.

In one use of the fastener, the headed end (5 is threaded into a body of plastic material so the opposite end projects in a position to serve as a stud. The portion l5 assists in securing the fastener in place. A

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. The method of forming a fastener which comprises rolling a blank having a body with a thin head at one end thereof between dies and as a part of the rolling operation bending the edges of the head axially outward from the end of the body.

2. Dies for rolling a fastener from a blank having a body with a thin head at one end, com prising faces cooperating with the body of the which comprises rolling a blank having a body with a head having portions projecting radially outward beyond the periphery of the body portion and displacing the projecting portions of the head radially inward.

5. Dies for rolling a headless fastener by the rolling process from a blank having a body with a head having portions projecting radially outward beyond the periphery of the'body portion, comprising faces cooperating with the body of the blank, and portions cooperatingwithtthe head to displace the projectingportions-thereof radially inward.

AXEL BOGGILD. JOHN DUCH. 

